mvc

 1:用properties属性文件描述链接资源！

              把需要经常变动的内容，放在属性文本资源文件中！需要的时候从属性文件中获取！

              扩展名:必须为properites!

              位置：开发阶段在src目录下！ 运行时会在classes目录下！

              构成：必须是key=value不允许跨行！

              Properties p = new Properties();

              p.load(Test.class.getResourceAsStream("/db.properties"));//用properties对象去读取资源文件

              System.out.println(p.getProperty("uname"));

              System.out.println(p.getProperty("upass")); 

              把jdbc的数据库连接采用属性文件的方式描述！

              static{//读取文本资源文件 只读一次

                            Properties p = new Properties();

                            try {

                                          p.load(JdbcUtil.class.getResourceAsStream("/db.properties"));

                                          driver = p.getProperty("driver");

                                          url = p.getProperty("url");

                                          uname = p.getProperty("uname");

                                          upass = p.getProperty("upass");

                                          System.out.println("资源文件初始化成功...");

                            } catch (IOException e) {

                                          // TODO Auto-generated catch block

                                          e.printStackTrace();

                            }

              }

分页：

              内存分页

                            List list = dao.findAll();已经查出所有数据了

                            页面只显示其中一部分

                            <c:forEach begin="1" end="10">

                            避免：

                            得总记录数：

                                          List list = dao.findAll();已经查出所有数据了

                                          int count = list.size();

                                           应该采用sql:select count(*) from table 

              物理分页:

                            每次分页只取数据表的一部分数据！

                            应该采用数据库提供的物理分页语句！

                            mysql:

                            SELECT * FROM userinfo LIMIT 0,5

已知：

              pageSize:4

              count:13

              共几页:

              if(count%pageSize==0)

                            count/pageSize

              else

                            count/pageSize+1

              (13+4-1)/4:公式

              (count+pageSize-1)/pageSize

 java的基础数据类型和基础数据类型的包装类是按照值传递的！相当于传递的是副本！

对象，和数组 是按照引用传递的!

创悦（深圳）投资管理有限公司

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mvc

原文：http://www.cnblogs.com/Creajoy/p/5670416.html